ScienceJuly 18, 2026

astrometry

uh-STROM-ih-tree

Definition

The branch of astronomy that involves precise measurement of the positions, motions, and distances of celestial bodies.

Etymology

Derived from the Greek words 'astron' (star) and 'metron' (measure), it emerged in English to describe the mathematical and physical mapping of the heavens.

In the news

Astrometry is the specific technique used by astronomers to identify a hidden black hole by tracking the subtle, rhythmic motion of a nearby star over many years. It is significant because it allowed researchers to detect an object that was not emitting light or radiation.

NASA space telescopes detect tiny black hole in ancient star cluster

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Mashable

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